52 Biology in America 



class room of the well equipped biologist contains not only 

 the most modern microscopes (the instrument par excellence 

 of biological research) but microtomes for cutting sections 

 of microscopic material down to a twenty-five thousandth of 

 an inch in thickness; electrically controlled incubators, where 

 cultures of microscopic organisms and growing tissues can 

 be held within one degree F. of any desired temperature; 

 electrically driven centrifuges running at speeds of from three 

 to four tliousand revolutions per minute; projection appa- 

 ratus for projecting pictures, microscopic preparations, and 

 even living animals themselves upon the demonstration screen, 

 or drawing board ; apparatus for taking photographs of these 

 preparations at magnifications of from one to two thousand 

 diameters; delicate balances for weighing down to a twenty- 

 five thousandth of an ounce or less, and hot houses and 

 aquaria where living material for study may be always avail- 

 able. 



Such is some of the more common apparatus of the biolog- 

 ical laboratory. In laboratories devoted exclusively or pri- 

 marily to research, such as those at Woods Hole, Cold Spring 

 Harbor and elsewhere, reference to which will be made below, 

 apparatus of a special, and often costly type is usually found 

 in addition to the more common equipment outlined above. 



The biological laboratory of college or university is not 

 however a separate institution especially devoted to biology, 

 but merely a part of a larger institution dedicated to the dis- 

 semination and advance of all knowledge. Yet it is through 

 this channel that the greatest contributions to biology have 

 thus far come. In considering biological institutions however 

 we are primarily interested in those devoted exclusively to 

 this science, including our museums, government and endowed 

 laboratories, and others of similar character. 



The early history of biology in America was as we have 

 seen closely associated with the museums. From their mem- 

 bers in many instances went forth the collectors who accom- 

 panied the early explorers into virgin forests, across trackless 

 prairies and through the wild defiles of mountain fastnesses. 

 And it was to the museums that these collectors returned to 

 study and describe the treasures whicli they had found. 



Numerous as are the splendid natural history museums 

 in America, space limits us to a brief consideration of but 

 three, as typical of the achievements of American science in 

 this field. Of our larger museums, especially those devoted 

 primarily to natural history, the earliest established was the 

 Academy of Natural Sciences in Philadelphia. The dawn of 

 the year 1812 was darkened by the cloud of war which hung 

 low over America, The one amusement house in Philadelphia, 



